The tragedy of an Indonesian domestic helper being killed by a fallen decaying tree branch has again reminded Hong Kong of its long-running shortcomings in tree management, local experts said on Wednesday.

Ken So Kwok-yin, chief executive of the Conservancy Association, an NGO involved in environmental issues, suggested improper pruning could have caused the snapping of the branch from the Indian rubber tree.

Veteran landscape architect Patrick Lau Hing-tat said a lack of resources and an absence of a licensing system for tree workers had rendered quality control difficult.

Their comments came a day after the death of Jumiati Supadi, 48.

She was struck on the head by a falling 4½-metre-long branch that weighed 30kg, as she was walking with her employer along New Clear Water Bay Road in Sau Mau Ping.

The incident marked the fifth tree-related death in the city over the past 10 years, with critics saying little progress had been made since the last fatality, in which a heavily pregnant woman was killed by a falling tree in Mid-Levels in 2014.

The Housing Department, which is in charge of managing the tree in question, said it hired contractor City Landscaping Company to assess the tree in January and June, but the company did not identify any “issues that needed immediate follow-ups”.

Victor Man, of the contractor, told the Post that “everything was based on the instruction from the department”.

Lau, a long-time champion of better greening locally, said the department tended to choose contractors who charged the lowest rates due to the city’s low budget on greening.

Last year, the government spent about HK$400 million (US$50.9 million) on tree management, compared to HK$10 billion in public works.

He added there was no licensing system for tree workers, so contractors were free to hire those who were underqualified, adding to the difficulties in quality control.

“The industry is very unhealthy,” Lau said. “Without a licensing system, there is no imminent danger of repealing any licence, and it will be very difficult to hold companies or individuals responsible and prevent misconduct.”

The industry is very unhealthy ... it will be very difficult to hold companies or individuals responsible

Patrick Lau Hing-tat, landscape architect

Lam Tak-chak, who trains arborists for the Vocational Training Council, agreed, adding that the Housing Department only paid HK$200 for a tree assessment report.

Lam, who inspected the fallen tree on Tuesday, said the contractor could have spotted the risks before the tragedy happened if given enough time and manpower.

He added that many tree assessment reports submitted to the department came with a disclaimer that stated the contractors would not be responsible for whatever happened to the inspected trees in the future.

However, lawyer Daniel Wong Kwok-tung believed the disclaimer would not limit the liability to casualty.

“The exemption effect is close to zero,” Wong said of cases involving a casualty.

Chief Executive Carrie Lam Cheng Yuet-ngor once promised to “actively consider” legislation on tree management when she was the secretary for development from 2007 to 2012.

However, in May this year, Lam pointed to London, New York and Melbourne as examples of cities that managed trees properly without the need for legislation.

A Development Bureau spokeswoman said Hong Kong’s existing system was similar to that of those cities.

She said the government was helping the horticulture and arboriculture industry to develop standards for related higher education courses. The courses, she added, could provide “the basis of establishing a system to standardise and enhance” the industry’s quality. These efforts would be completed by the end of next year.

A Housing Department spokeswoman said City Landscaping was involved in risk assessment of some 21,000 trees under the department in Kowloon East.

She said the department would investigate the accident. It expected preliminary results to come in two weeks.

Speaking on a radio programme on Wednesday, So, an arborist, said he had seen numerous “pruning wounds” on the Indian rubber tree in question when he inspected it after the accident.

He noted improper pruning could lead to decay or fungal infection of branches.

Another tree expert, Jim Chi-yung, a geography professor at the University of Hong Kong, also suggested after visiting the scene on Tuesday that fungus had caused the decay, while a lack of space for the tree to grow had weakened its immune system.